[mowaca]

We have two bedrooms over the garage, one of them is always cold/hot depending on the season. It isn't that bad in the winter but in the summer its hot in there at night. I thought it was just the garage but I broke down yesterday and troubleshooted the venting and I think it is not connected at all?

With the fan on there is zero airflow and the temp only goes down about 4 degrees with the hvac on, right bedroom is over 20 degrees diff. There's nothing in there as far as I can tell (used my phone camera with a flashlight to look). There's a rather long run that comes upstairs from the basement to these two rooms. The damper is open. I unscrewed the sheet metal screws and disconnected the duct & no measurement tools but the air feels like it has good pressure. After I did this, both rooms have no air, reconnected it and the right bedroom has air, left room has no air.

Both of these rooms have some kind of flexible ductwork. My guess is in the garage ceiling the left bedroom is disconnected (I'm actually suspicious this was never connected...20 year old house!). I am very hesitant to call a random HVAC contractor w/o some kind of script of questions to ask so I get the right person out to fix this who actually knows what to do and has the right tools. I'm hesitant to keep DIYing this - I have no idea what to do other than just take the ceiling apart. I live near Columbus, OH if any one has a recommendation, thanks!

 

[user_12345a]

Assuming you don't have access to the duct run - You'll need to a long flexible snake camera to diagnose this yourself - some are cheaper due to plugging into or communicating with a smart phone with wifi or bluetooth instead of using a screen.

If you see the break, mark the snake camera, pull it out and measure distance to roughly determine where the problem is.

It's possible the duct has been crushed instead of disconnected.

 

[supers05]

I would suggest DIY looking for the problem. A tech that even wants to look for it won't be cheap. But if you call up a company and tell them that you have a run or 2 that's not connected somewhere, but the hvac otherwise works fine, they will send someone who can deal with it.

Either way it'll require opening the drywall. Without a snake like user suggested, you'll be making several holes in the drywall. (might be cheaper than the snake rental depending on your DIY abilities.) Personally, I would cut open the ceiling.

 

[mowaca]

Thanks - I could cut a big hole or two and look around at this point but I’d rather not - the snake is a good idea. What should the flexible duct connect to - some kind of metal T near the wall where it comes up from the basement?

Drywall repair is cheaper than my home warranty deductible but ductwork is covered as far as I know. And I suspect there’s no place to connect this at all - it’s a construction error.

I’ll call around this week and see if they can send someone with a camera snake.Thanks!